Question 1

How many units is a 2 mg dose of TB-500 (5mg vial, 3ml diluent)?

Accepted Answer

120 units on a standard U-100 insulin syringe (1.2 ml). Mixing a 5mg vial of TB-500 with 3ml of bacteriostatic water gives a concentration of 1.67 mg/ml. On a U-100 insulin syringe that means: 2 mg = 120 units · 2.5 mg = 150 units · 5 mg = 300 units.

Question 2

What is the concentration of 5mg of TB-500 in 3ml?

Accepted Answer

5mg ÷ 3ml = 1.67 mg/ml.

Question 3

Which syringe do these unit marks refer to?

Accepted Answer

A standard U-100 insulin syringe, where 100 units = 1 ml. On U-50 or U-30 syringes the same volume reads as half or 30% of the U-100 marks. These are mathematical conversions for organizational purposes only — not medical advice.

Dose	Draw volume	U-100 units
2 mg	1.2 ml	120 U
2.5 mg	1.5 ml	150 U
5 mg	3 ml	300 U

TB-500 5mg in 3ml — syringe units chart